The former boy bander spoke out about his struggle with an eating disorder in his new book, Zayn. Malik said the intensity of his jam-packed schedule at the height of One Direction's popularity led him to skip multiple meals in a row, sometimes for multiple days. "Something I've never talked about in public before, but which I have come to terms with since leaving the band, is that I was suffering from an eating disorder," he wrote. "It wasn't as though I had any concerns about my weight or anything like that, I'd just go for days — sometimes two or three days straight — without eating anything at all. It got quite serious, although at the time I didn’t recognize it for what it was."

DEMI LOVATO

Lovato famously battled an an eating disorder in the spotlight, entering a treatment facility for anorexia and bulimia at 18 years old. "I'd be lying if I said there weren't days where I just want to stay in bed all day because I'm ashamed of my body," she told PEOPLE shortly after leaving the facility. "It's a struggle I'll probably have to deal with for the rest of my life. But I have so much life to live; I don't want to waste it." During an interview with American Way, the singer candidly discussed growing up with a mother who suffered from an eating disorder and how an early introduction to the beauty pageant scene affected her self-image. "Even though I was 2 or 3 years old, being around somebody who was 80 lbs. and had an active eating disorder … it's hard not to grow up like that," she told the magazine. "I'm nowhere near having children, but already I ask myself questions. My grandma had bulimia, my mom had it, I had it, and hopefully my kids won't have it, but it's kind of like addiction. It's hereditary." As for beginning her pageant career at the age of 7, Lovato says, "My body-image awareness started way before that, but I do attribute a little of my insecurities to being onstage and judged for my beauty."

GINGER ZEE

She flaunts her assets weekly on Dancing with the Stars, but Zee struggled to find contentment with her body in her adolescence. On the semi-final night of DWTS, she opened up about her battle with anorexia, which she says was at its worst from ages 10 to 14. "It's a moment in my life that I've not shared with a lot of people," she told PEOPLE. "It's not something I'm proud of because it's a disease that I chose." She credits her mother and step-father for helping her through. "My stepfather is a saint. He came into our lives and he taught me about nutrition and self love and once I started to learn about taking calories in and working calories off, then I got obsessed with working out," she said. "Everybody goes through those stages. He helped me to get out of that moment in my life."

ALEXA PENAVEGA

Zee wasn't the only DWTS contestant to open up about an eating disorder on the show. After experiencing a childhood in the spotlight, PenaVega developed bulimia in response to a movie producer telling her she was too fat. For six years, she struggled to overcome the disease. "You read textbooks and it's just so, well, textbook. 'This is how you get over bulimia.' But it is so much deeper than that," she said. "I wish I'd had somebody who could have told me, 'It's scary.' You struggle giving it up. You want to get rid of it but you struggle because, in a strange way, you enjoy it."

KESHA

Well before her legal troubles with her label and allegations of sexual assault against Dr. Luke, Kesha was struggling with another issue – her eating disorder. The star completed a rehab program for her disorders in 2014 and opened up to Vogue about her darkest times a year later. "There was a lot of not eating – and I started to think being hungry to the point of feeling almost faint was a positive thing," she said. "The worse it got, the more positive feedback I was getting. Inside I was really unhappy, but outside, people were like, 'Wow, you look great.'"

ZOË KRAVITZ

Kravitz experienced some bumps on the road to success – and a big one came in the form of her battle with anorexia and bulimia, which started as a teenager and followed her into adulthood. It was her star-studded upbringing, she says, that made her have a difficult time loving herself. "I think it was part of being a woman, and being surrounded by [fame]," she told Complex magazine. "I think it was definitely about being around that world, seeing that world. I felt pressured."

BEVERLY JOHNSON

Decades after she became the first African-American to appear on the cover of Vogue, iconic supermodel Beverly Johnson opened up about the dangerous diets she employed to stay on top in the modeling world. "I was eating nothing, zero," she said in her book The Face That Changed It All. "I drank black coffee, a sip of broth if things got tough, and in the evening, a glass of champagne as a pick me up. We didn't even drink water. We thought it was was fattening." This sort of behavior was encouraged: "The skinner you were, the more fabulous you were."

CANDACE CAMERON BURE

Though she shot to childhood stardom on Full House, Bure says that it wasn't until the show wrapped that she developed an eating disorder. She moved to Montreal – a city where she didn't know many people – for her husband's hockey career, and not working for the first time since she was five years old, Bure felt isolated and lost. "My husband would play away 41 games out of 82 during hockey season," she said. "I sat lonely so many nights not knowing what to do with myself. But there was always one friend that was always there, that was so readily available anytime I wanted, and that for me was food." She fell into a cycle of binging and purging that continued on-and-off for years. "It was never about the weight for me," she told PEOPLE. "It was an emotional issue."

ZOSIA MAMET

Girls star Mamet opened up to Glamour about her eating disorder, which she said is something she's battled since childhood. The Girls actress was told she was fat for the first time when she was just eight years old. "I'm not fat; I've never been fat," she said. "But ever since then, there has been a monster in my brain that tells me I am." Mamet says that her mother's issues with eating shaped her own view of her body. "I know that my mother's treatment of me stemmed from her own issues with her body," she said. "She struggled, so I struggled."

SHAWN JOHNSON

Along with her chance at Olympic gold came monumental pressure for Johnson – starting at a young age. While training as an adolescent and teen, she severely restricted her diet, eating no carbs or as few as 700 calories a day. "I was always the very strong, powerful, muscly, bulky gymnast and I felt like people always wanted me to be thinner and lighter and leaner," she told PEOPLE. "And as a 12-year-old, the only way I really understood how to achieve that was to eat less and restrict myself. I remember kind of obsessing over it."

MOLLY SIMS

The former Sports Illustrated swimsuit issue model says that during her earlier days in the industry, she would do pretty much anything to stay at a size 0 – walking up to 14 miles a day to do so. “It was very difficult to stay the weight that you were supposed to stay," she told the Huffington Post. For me, I'm genetically blessed in certain ways, but in terms of having the weight be a certain size 0, it was very hard. I didn’t eat sometimes for a couple of days.”

PORTIA DE ROSSI

She's been working since her childhood, and De Rossi can date her struggles with eating back to the beginning of her career. "I didn't eat for 10 days before," de Rossi said of her childhood modeling days. "I'm up on this catwalk, and I'm a little kid and posing and trying to be sexy and strutting around and all the other models are making fun of my bushy eyebrows." She then continued to struggle with her eating disorder into adulthood, which she chronicled in her book, Unbearable Lightness.

HILARY DUFF

Like many young stars, Duff admits that back in her teenage years, she definitely slipped into unhealthy territory when it came to eating. "I was too thin," Duff told PEOPLE. "That was not a healthy place for me. I was so unhappy. I remember my hands cramping because I wasn't getting enough nutrients."

TALLULAH WILLIS

At just 13 years old, Willis said a "switch flipped," and she started to hate herself. "I thought, I am a hideous, disgusting-looking person," she told Teen Vogue. "I might be nice and I might be kind, but I'm a really unattractive human being." That mindset continued throughout her teens, until eventually, her older sister Scout stepped in, and she started treatment. In January 2015, Willis said she was on the road to recovery. "I can say that I'm getting to that place where I'm starting to feel OK with myself, bit by bit."

NICOLE SCHERZINGER

It's not all song and dance for the former Pussycat Doll and X Factor judge. She battled bulimia for eight years, at the height of Pussycat Dolls fame. "It is such a horrible, paralyzing disease and it was such a dark time for me," she told Cosmopolitan UK. "I didn't think anyone knew in my group or in my family because I hid it that well, I was so ashamed. I knew it wasn't normal or healthy because I was hurting myself through this cycle of disordered eating. It was my drug, my addiction. It's an endless vicious cycle." Today, she's committed to doing things differently: "I’m never letting that happen again."